Copper base alloy



Patented May 22, 1934 UNITED. STATES PATENT OFFICE 1,959,509 COPPER BASE ALLOY Sam Tour, Englewood, N. J., assignor to Lucius Pitkin, Inc., a corporation of New York No Drawing. Application June 14, 1930, Serial No. 461,260

7 Claims. (01. 75-1) Many copper base alloys have been used for 50% or more of copper, .1% or more of silicon, industrial purposes notwithstandingthe difficuland from 1% to 6% of bismuth. These three eleties which have been encountered in producing ments may be mixed together to constitute the and. working them. An important series of such only components of the alloy, or other metals alloys has contained copper and silicon, either may be added to them. Thus, modifications of 60 with or without the addition of other metals such the invention may include iron, manganese, as zinc, iron, manganese, nickel, cobalt, etc.. in and/or zinc in the proportion of .1% or more of various proportions. Such alloys are advantaeach or of any one of them, in addition to the geous because of their ductility and tenacity due copper, silicon, and bismuth. In referring to the 10 t0 h presence 0f pp hardness imparted by p rcentages of silicon, iron, manganese and zinc 65 the silicon, and other properties as contributed as being .1% or more, I have in mind the peror modified by the other metals. One serious obcentages used heretofore in producing alloys of J tion t ese y h w s t at th y are these metals, it being known that the percentages qu tough and stringy and therefore ditficult above the minimum may vary to a considerable to machine-so much so that their use has been extent. My invention consists primarily in add- 70 somewhat limited. ing to these known alloys a percentage of cis- It is desirable for many purposes to provide muth suflicient to produce the desired. results. pp base alloys with free Cutting qua ities, Of course, my invention is not intended to be and this has been done in the past by adding lead confined to'such known alloys and is believed to 26 to such alloys which do not contain silicon. EX- be applicable to any copper base alloy containing 75 perience has shown that the addition of lead to silicon. copper alloys containing silicon does not give The new alloy embodying 'the invention can the desired machinability and free cutting propbe readily produced by merely melting the com erties, for the reason that the lead reacts with stituent elements in any preferred type of furthe silicon to form a silicide which causes 10- nace and stirring them together in a manner 80 calized hard spots and decided amounts of segwell known to those skilled in the art. The bisregation, as Well as Causing 1058 Of ead from muth in the mixture greatly increases the fluidity the molten metal during the melting. It has of the alloy in the molten state and this, coutherefore been necessary in the p st t sacrifice mm with the fact that the bismuth reduces the 30 the properties imparted by the silicon in order overall shrinkage in.coo1ing, renders the alloy 5 to obtain increased machinability, but the presparticularly well adapted for casting purposes, ent invention overcomes the above-mentioned giving much sharper detail than has been posand other objectionable features of the prior art sible with prior art copper base alloys. However, and provides a copper base alloy including silithe alloy is not limited to use as a, casting metal,

con and a metal other than lead. but, by reason of its ductility and malleability, 90

In solving this problem, I have found that it can be worked either hot or cold by rolling, bismuth, contrary to the accepted teachings of heating, spinning, drawing, or otherwise, as dethe art, is exceptionally well suited for increassired. And, as-previously stated, it possesses to ing the mach nability of copper-silicon alloys 2. high degree the much desired free cutting without sacrificing any important properties. properties which make possible its easy machin- 95 Thus, in carrying out the invention, I provide a ing, whether by drilling, boring, turning, shapcopper base alloy with silicon containing from ing, filing, or otherwise.

1% to 6% of bismuth, this alloy giving excellent Having thus described my invention, what I results regardless .of whether it is of the yellow claim is:

brass variety (approximately copper), or of 1. An alloy consisting of 1 to' 6% bismuth, .1 1

the red brass or bronze variety (approximately to 6% silicon, .1 to 35% zinc and .l'to 6% of or more copper}. Of course, the amount of one or more metals of the group consisting of bismuth to be added to any given copper base iron, manganese, nickel and cobalt, and the realloy containing silicon is variable, dependent mainder substantially copper.

50 upon the basic properties of that alloy without 2. The method of rendering machinable, an althe bismuth, and upon the degree of free cutting loy consisting of copper or copper and one or-more qualities desired. In fact, the invention is suselements of the group consisting of zinc, iron, ceptible of numerous variations in the relative manganese,,nickel and cobalt to which silicon proportions of the component elements. has been added for the purpose of hardening,

55 By w y of p the w all y aycontain said method consisting in adding bismuth to the alloy in quantitiessufficient to produce the desired degree of machineability.

3. The method of imparting fluidity to an alloy in the molten state, consisting of copper or copper and one or more elements of the group con .1 to 6% silicon,'about 1 to 6% bismuth and characterized by having increased fluidity in its molten state due to the presence of bismuth.

6. A copper base alloy containing from about .1 to 6% silicon, about 1 to 6% bismuth, about .1 to 35% zinc-and characterized by being readily machineable due to the presence of bismuth.

7. A copper base alloy containing from about .1 to 6% silicon, about 1 to 6% bismuth, about .1 to 6% of one or moremetals of the group, consisting of iron, manganese, nickel and cobalt and characterized by being readily machineable due to the presence of bismuth.

SAM TOUR. 

